1. Field of the Invention
The invention relates generally to inflation systems wherein a stored chamber of compressed gas is used to inflate an inflatable device in automatic response to some occurrence. More particularly, the invention relates to such an automatic inflation system operable in and around water, such as flotation systems and emergency locating systems, and also with devices utilizing lighter than air gases to automatically inflate balloons which will rise in the atmosphere.
2. Description of the Prior Art
Automatic inflators are well known in the fields of life-saving and signalling equipment. Among such prior disclosed automatic inflators are the following: U.S. Pat. No. 4,223,805 granted to Mackal; U.S. Pat. No. 3,997,079 granted to Niemann; U.S. Pat. No. 3,266,669 granted to Vuyosevich; U.S. Pat. No. 3,490,648 granted to Fujimoto; U.S. Pat. No. 2,722,342 granted to Fox; U.S. Pat. No. 3,610,470 granted to Waters; U.S. Pat. No. 3,597,780 granted to Coyle; U.S. Pat. No. 3,449,777 granted to Hattori; U.S. Pat. No. 2,919,833 granted to Wolshin; and U.S. Pat. No. 3,077,288 granted to Henry. All of these patents disclose devices, however, which are designed in a manner such as to have their automatic operation be responsive to submersion in water through the use of various systems such as dissolution of a water soluable tablet, weakening and resulting rupture of a paper band following wetting, energization of a battery by allowing water into the battery to become the electrolyte, or by the increasing of the conductivity between electrodes which results from immersion of the electrodes in water. As such, all of these devices are unsuitable for applications where immersion in water is a normal condition and cannot be the occurrence which initiates the automatic inflation. These devices are also unsuited to situations where immersion in water is never the case, and not the desired condition for which an automatic response is desired.
Automatic signalling and locating devices have long been known. U.S. Pat. No. 4,063,323 granted to Salvarezza discloses an automatically separating system which inflates a flotation device and which automatically emits smoke and operates a flashing beacon. Such a device provides aids for visual search as well as a radio signal or a radar beam to assist in locating the device. It does not, however, provide for elevation of the signalling devices by inflatable masts.
Various applications of detonation devices for puncturing the seal on compressed gas containers have been disclosed by the prior art. In U.S. Pat. No. 4,161,797 granted to Ruscigno as well as the patents issued to Vuyosevich, Coyle, Hattori, and Henry all referred to above, have all described such applications of detonating devices. Similarly, numerous designs are available for providing for passage of the compressed gas past the puncture pin in a seal rupturing system. The Fujimoto '648 patent, discusses various pin designs which allow the gas to exit the compressed gas container following puncture of the seal without the need for removing the pin. Removing the pin is an alternative approach which can be accomplished either by the method disclosed by the Wolshin '833 patent or by the method described in U.S. Pat. No. 3,547,165 granted to Butterworth.
The length of time required between the occurrence intended to cause the automatic response and such automatic response has been addressed by the Vuyosevich '669 patent, from the standpoint of shortening such time period. Nowhere, however, has the prior art recognized that there could be circumstances where such time period might need to be intentionally lengthened.
A particular need exists for an emergency locating device for underwater remote controlled vehicles which become lost. Underwater remote controlled vehicles occasionally get their operating tether cable tangled which makes it impossible to retrieve the vehicle. Remote control of severance of the tether cable at the vehicle allows said vehicle to rise to the surface and drift after it has been severed from the tether cable. An emergency locating system for such a vehicle could not be water activated, but needs activation by some means related to the vehicle being cut loose. At the same time, it is not appropriate for such an emergency locating system to activate until the vehicle has had time to float to the surface.